Chair construction



June 13, 1961 E. F. HAMILTON 2,938,398

CHAIR CONSTRUCTION Filed Oct. 21, 195"! 2 Sheets-Sheet 1 INVENTOR. Ee /2L [HF/rm 7on5.

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June 13, 1961 E. F. HAMILTON 2,988,398

CHAIR CONSTRUCTION Filed Oct. 21. 195'? 2 Sheets-Sheet 2 INVENTOR. 157991. F /1fln7/z Ta/v,

BY K %?J Trap/V575,

United States Patent F Earl F.

This invention relates to chairs, and more particularly to ofiice chairs having adjustable backs.

It is an object of my invention to provide a chair of the type indicated, which will lend itself to construction with sheet-metal and metal-tubing, which can be simply and economically manufactured, which will prove sturdy and durable in use, and which will possess a pleasing appearance. Another object of the invention is to provide an improved means for adjusting a chair back horizontally and vertically with reference to the chair seat.

In carrying out my invention in its preferred form, I provide a chair base having an upwardly projecting seatsup-porting rod, the rod being adjustable with respect to the base and the floor to provide for adjustment of the seat height. Pivotally connected to the chair seat .on a horizontal transverse axis is a tilting plate carrying a back support thereby permitting the chair back to be tilted with respect to the chair seat. The back support comprises a frame having two generally parallel arms the lower ends of which extend beneath the seat and are slidably received in the tilting plate for forward and rearward adjustment of the chair back, and means are provided for releasably holding such arms in the desired position of horizontal adjustment. Desirably, further adjustability is provided by mounting a back rest to a pair of plates vertically movable on the back support for adjusting the back rest height, with means provided for releasably holding the plates in the desired vertical position.

Convenienlty, the back support is provided with bumper means disposed rearward-1y of its arms and adapted to abut a wall or other obstruction with which the chair back may come in contact for preventing damage to the chair or said wall.

The accompanying drawings illustrate one embodiment of my invention. In such drawings:

FIG. 1 is a side elevation of a chair embodying my invention;

FIG. 2 is a front elevation of the chair shown in FIG. 1;

FIGS. 3 and 4 are rear and side views respectively of the upper end of the back support;

FIG. 5 is a horizontal section taken on the line 55 of FIG. 4;

FIG. 6 is a vertical section taken on the line 6-6 of FIG. 1; and

FIG. 7 is a horizontal section taken on the line 7--7 of FIG. 6.

The chair illustrated in the drawings comprises a base 10 which slidably receives a vertical seat-supporting rod 12 releasably locked in vertical position by a lock-plate mechanism 14. Swivelled on the rod 12 and adapted to move vertically therewith is a chair seat 16 having a seatpan 18 in the form of a sheet-metal stamping which forms the basic structural support for the seat 16. The pan 18 is fixedly mounted, as by bolts 28, to a bracket 22 rotatably received on the supporting rod 12 to permit rotational movement of the chair seat 16. A pair of ears 24 provided at the rear of the bracket 22 are operatively connected to a tilting plate 26 pivotally joined to the ears 24 by a pin 28 defining the tilting axis of the chair back. The tilting plate 26, which desirably is a sheet-metal stamping, has each of its lateral edges bent into inwardly directed channeled extensions 39, each having a longitudinal slot 32 cut in its vertical web portion.

As shown in FIG. 1, the back for my chair is formed Patented June 13, 1961 from a back support 34 to which a back rest 36 is secured. The support 34 is desirably a length of metal stock bent into a generally U-shape and having its lower end portions 38 bent to extend forwardly in parallel relation below the chair seat 16. The horizontally extending portions 38 of the back support 34 are slidably received in the channeled extensions 30 of the tilting plate 26; thus permitting the chair back to be tilted with the plate 26 about the axis of the pivot pin 28, and permitting the back rest 36 to be adjusted forwardly and rearwardly in such plate for the comfort of the user. To hold the back support 34 in any desired position of forward and rearward adjustment, the horizontal back support portions 38 are provided with openings 40 receiving bolts 42 which also extend respectively through the slots 32 in the extensions 30 of the plate 26. Desirably each bolt is non-rotatable in its portion 38 and includes a hand nut 44 by which it can be tightened to secure the back support in fixed position in the plate 26.

Preferably, the channel-like plate extensions 30 are so formed that their upper and lower walls diverge with respect to each other inwardly of the chair seat, as shown in FIG. 6, so that when the bolts 42 are tightened the portions 38 of the back support will be drawn into wedging engagement between such upper and lower walls. This arrangement takes up all lost-motion in a vertical plane between the portions 38 and the tilting plate 26, and prevents the back support from rocking relative to the tilting plate about the axis of the bolts 42.

Rearward tilting of the back support 34 and the tilting plate 26 is resiliently opposed by a spring 43 which acts in known manner between the tilting plate and a bolt 45 connected to the bracket 22.

The back rest 36 is desirably formed with a padded front portion mounted on a structural supporting frame 46 conveniently formed from a sheet-1netal stamping. Laterally disposed on the frame 46 is a pair of brackets 48 pivotally secured, as by rivets 50, to a pair of mounting plates 52 through which it is connected to the support 34. As shown in FIGS. 4 and 5, each of the mounting plates 52 is provided with a vertically extending channel portion 54 slidable upon the back support 34 and having a plurality of vertically spaced openings 56. To hold the back rest 36 in the desired vertical adjustment, clamp bolts 58 in the back support 34 are passed through openings 56 in the plates 52 with their threaded ends receiving knob-like nuts 60 for retaining the plates on the bolts. By disposing the bolts 58in the proper openings 56 the back rest 36 can be vertically adjusted on the back support to the desired position for the comfort of the user.

A bumper 64 having a longitudinally extending head 66 extending rearwardly of the back support 34 is secured to the inner surface of the back support at its upper end. The bumper 64 may be formed from any suitable material, such as rubber or the like, which will not scratch or mar a wall or other obstruction with which the chair may come in contact. The bumper 64 is secured to the back support 34 by a metal strip 68 overlying the bumper and a plurality of screws 70, preferably of the self-tapping type, which extend through the strip and bumper and are received in the back support 34.

Although I have described a chair back construction which combines vertical and horizontal adjustability with rearwardly disposed bumper means, it is to be understood that any of these features may be used individually or in combination without departing from the spirit and scope of my invention.

Certain features of the bracket 22 and its combination with the tilting plate 26 are more fully set forth and described in my copending application Serial No. 691,392, filed October 21, 1957 I claim as my invention:

1. In a chair having a seat provided with a tilting plate operable for tilting the chair back with respect to the seat, a, back support'having a pair of arms extending below said seat, said arms being slidably received in channel-like extensions on said tilting plate, each of said extensions having opposed walls between which one of said arms is received and which converge relative to each other in one direction transverse to their extent, and a clamp bolt for drawing each of said arms into wedging engagement between the converging walls of the associated extension, and a back rest disposed on said back support above the plane of the seat.

2. In a chair having a seat provided with a tilting plate operable for tilting the chair back with respect to the seat, a back support having a pair of arms extending below said seat, said arms being slidably received in channeled extensions on said tilting plate for forward and rearward adjustment of the back support, each of said arms having binding means mounted thereon and vslidably received in a longitudinal slot in said channeled ing the forward and rearward adjustability of the back support.

4. In combination with a chair having a seat and a back rest supported above said seat, a back support of metal-tubing having a pair of arms extending upwardly from operative connections to said seat, a pair of plates pivotally connected to said back rest and slidable on said back support arms for vertical adjustment of the back rest, said plates being disposed inwardly from the lateral edges of the back rest and having elongated channels slidably receivable against the back support arms, each of said channels partially circumscribing one of said arms over substantial vertical and peripheral extents, and means interconnecting each of said plates to one of said back support arms for releasably retaining the back rest in the desired position of vertical adjustment.

5. A chair as set forth in claim 4 with the addition that one of the channel legs on each of said mounting plates is provided with a plurality of openings, and said means comprises set screws received in said openings and engageabfe with the back support arms for retaining the back rest in the desired vertical adjustment.

References Cited in the file of this patent UNITED STATES PATENTS 2,260,976 Jones Oct. 28, 1941 2,360,788 Murphy Oct. 17, 1944 2,547,455 Freeman Apr. 3, 1951 2,599,301 Van Buren June 3, 1952 2,680,474 Fritz June 8, 1954 2,692,012 Cramer Oct. 19, 1954 2,703,601 Wood Mar. 8, 1955 

